항만 내외에서 물리이화학적 환경요인과 식물플랑크톤 군집의 계절적 변동

Abstract

This study aim to understand the seasonal variations of physico-chemical factors and phytoplankton communities at inner and outer ports. We seasonally investigated environmental and biological factors in surface water at Pusan, Ulsan, Incheon and Gwangyang ports from February 2007 to August 2008. During the study periods, water temperature showed seasonal fluctuation due to air temperature at all study areas. Salinity was more than 32 psu at all study areas in winter, which showed less than 28 psu at Incheon and Gwangyang ports in summer. Also, nutrients (nitrite, nitrate, ammonia, phosphate and silicate), pH, DO, TSS, COD and chlorophyll a showed seasonal fluctuations. Water temperature was higher 0.3-1.5℃ outside than inside stations except at Incheon port in summer. Nutrients showed higher concentrations at Incheon and Gwangyang ports than Pusan and Ulsan ports, which were high concentrations at inside stations. In phytoplankton communities, a total 84 taxa were identified to the following taxonomic groups: bacillariophyceae (70), euglenophyceae (1), chrysophyceae (2) and dinophyceae (11). Diatom group which occupied one of the major components in phytoplankton communities was high in spring, autumn and winter seasons. The phytoplankton showed highest standing crops in summer (5×105 cells L-1) at Pusan port, 9×105 cells L-1 in spring at Ulsan port, 4×104 cells L-1, 13×105 cells L-1 in winter at Incheon and Gwangyang ports. Standing crops of the inside stations were higher than those of outside stations at Pusan, Ulsan and Gwangyang ports. Dominant species were Skeletonema costatum, Chaetoceors socialis and Cheatoceros pseudocrinitus at Pusan ports. At Ulsan port, dominant species were Sk. costatum and Detonula pumila. At Incheon port, dominant species were Sk. costatum and Paralia sulcata. Sk. cosataum and Odontella longicruis were dominated at Gwangyang port. As a result, physico-chemical factors showed seasonal variations and differences at inside and outs